Microquasar Feedback

Black holes and neutron stars can accrete matter from their binary companion stars. In the process, they can not only release large amounts of radiation (mostly in the X-ray band, which gives them their designation as "X-ray binaries"), but they can, under certain circumstances, launch relativistic jets - tightly funneled streams of relativsitic, magnetized gas. In this case, we also call the obect a "microquasar".

As this gas streams away from the compact object, it must eventually encounter the interstellar medium. Like jets from supermassive black holes, these microquasar jets can shock gas, push it aside into shells, and inflate diffuse "radio lobes" of synchrotron emitting plasma.

Professor Heinz's group is studying the dynamics and observable characteristics of this iteraction, both theoretically and through a program of broad-band observations of a number of objects.

For example, we have recently discovered a large-scale, jet-driven X-ray shock around the neutron star Circinus X-1. No other neutron star or black hole within our own galaxy shows anything like this. A careful analysis shows that the shockwaves are only about 1600 years old, a relatively recent phenomenon in astronomical terms, and that this neutron star is incredibly powerful.

While only a few dozen X-ray binaries suitable for such detailed study are known within the Milkyway, this observation clearly shows the power of deep observations of individual objects (a fact often forgotten in the era of survey science).